what is the basis of determining the direction of friction in case of rolling motion?? It increases or decreases angular velocity? For e.g - if a body is rotating clockwise, what will be the direction of friction ??

SOLUTION

In case of a rolling motion the direction which is opposite to the motion of a rolling body indicates the direction of frictional force.As we know that frictional force generally opposes motion so here friction is trying to oppose the rolling of the body.The angular velocity of the body here decreases.

If a body is rotating clockwise then the direction of friction will be anti-clockwise.